Field of the Invention
The invention relates to a sensor unit for actuating, i.e. for opening and/or closing, a vehicle door, in particular a tailgate, in a contactless fashion.
Description of the Background Art
For a user of a vehicle it is from time to time desirable to open or to close a vehicle door, in particular the tailgate of a trunk, in a contactless fashion. This is the case, for example, if the user uses both hands to carry an object such as, for example, a beer crate which is to be positioned in the vehicle's trunk.
At present, development work is being carried out on sensor units with proximity sensors which are arranged in the rear bumper of the vehicle and can detect a movement of the user's foot as a door opening request, whereupon a triggering signal for automatically opening (or else closing) the trunk is output by a control unit which is connected to the proximity sensors by signal technology. Such sensor units are frequently configured to output the triggering signal if the user extends his foot under the bumper.
It is desirable for such a sensor unit to be capable of reliably differentiating a specific characteristic movement of the foot, with which the door opening request is to be indicated, from other movements of the foot. For example, the sensor unit is to bring about the opening of the trunk if the vehicle driver carries out a kicking movement in the longitudinal direction of the vehicle under the bumper, while the opening process of the trunk is to fail to occur if the vehicle user moves his foot transversely with respect to the vehicles. This is intended to avoid, in particular, a situation in which the opening process of the trunk is triggered incorrectly if the user of the vehicle walks around the vehicle.